vpFeatureMomentGravityCenter.h

/****************************************************************************
 *
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2023 by Inria. All rights reserved.
 *
 * This software is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ViSP with software that can not be combined with the GNU
 * GPL, please contact Inria about acquiring a ViSP Professional
 * Edition License.
 *
 * See https://visp.inria.fr for more information.
 *
 * This software was developed at:
 * Inria Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
 * France
 *
 * If you have questions regarding the use of this file, please contact
 * Inria at visp@inria.fr
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Description:
 * Implementation for all supported moment features.
 *
 * Authors:
 * Filip Novotny
 *
*****************************************************************************/
#ifndef _vpFeatureMomentGravityCenter_h_
#define _vpFeatureMomentGravityCenter_h_
 
#include <visp3/visual_features/vpFeatureMoment.h>
 
#ifdef VISP_MOMENTS_COMBINE_MATRICES
class vpMomentDatabase;
  vpMomentObject obj(2); // Init object of order 2 because we need
                         // vpFeatureMomentBasic of order 1 (for vpFeatureMomentGravityCenter) which
                         // implies third-order moment primitives
  obj.setType(vpMomentObject::DISCRETE); // Discrete mode for object
  obj.fromVector(vec_p);
 
 
  vpMomentDatabase mdb; //database for moment primitives. This will
                        //only contain the basic moment.
  vpMomentBasic bm; //basic moment (this particular moment is nothing
                    //more than a shortcut to the vpMomentObject)
  vpMomentGravityCenter  gc; //gravity center
 
  bm.linkTo(mdb); //add basic moment to moment database
  gc.linkTo(mdb); //add gravity center to moment database
 
  vpFeatureMomentDatabase fmdb; //feature moment database to store
                                //feature dependencies
 
  //Declare and link moments to database
  vpFeatureMomentBasic fmb(mdb,0.,0.,1.,&fmdb); fmb.linkTo(fmdb);
  vpFeatureMomentGravityCenter fgc(mdb,0.,0.,1.,&fmdb); fgc.linkTo(fmdb);
 
  //update and compute the vpMomentBasic before computing vpMomentGravityCenter
  bm.update(obj);
  bm.compute();
  //update and compute the vpMomentGravityCenter before computing vpFeatureMomentBasic
  gc.update(obj);
  gc.compute();
 
  fmb.update(0.,0.,1.); //update the vpFeatureMoment with a plane
                     //configuration and compute interaction matrix
 
  fgc.update(0.,0.,1.); //update the plane configuration for gravity
                     //center feature and compute it's associated matrix.
 
  std::cout << fgc.interaction(1 << 1) << std::endl;
 
  return 0;
}
  \endcode
 
  This code produces the following output:
  \code
0  -1  1.5  3.5  -2.5  -1.5
  \endcode
 
  You can also use the shortcut selectors
vpFeatureMomentGravityCenter::selectXg or
vpFeatureMomentGravityCenter::selectYg as follows:
 
  \code
  task.addFeature(db_src.getFeatureGravityNormalized(), db_dst.getFeatureGravityNormalized(),
                 vpFeatureMomentGravityCenter::selectXg() | vpFeatureMomentGravityCenter::selectYg());
  \endcode
  This feature depends on:
      - vpFeatureMomentBasic
 
  Minimum vpMomentObject order needed to compute this feature: 2.
*/
class VISP_EXPORT vpFeatureMomentGravityCenter : public vpFeatureMoment
{
public:
  vpFeatureMomentGravityCenter(vpMomentDatabase &database, double A_, double B_, double C_,
                               vpFeatureMomentDatabase *featureMoments = NULL)
    : vpFeatureMoment(database, A_, B_, C_, featureMoments, 2)
  {
  }
  void compute_interaction();
  const char *momentName() const { return "vpMomentGravityCenter"; }
  const char *name() const { return "vpFeatureMomentGravityCenter"; }

  static unsigned int selectXg() { return 1 << 0; }

  static unsigned int selectYg() { return 1 << 1; }
};
 
#else
class vpMomentDatabase;
class VISP_EXPORT vpFeatureMomentGravityCenter : public vpFeatureMoment
{
public:
  vpFeatureMomentGravityCenter(vpMomentDatabase &data_base, double A_, double B_, double C_,
                               vpFeatureMomentDatabase *featureMoments = NULL)
    : vpFeatureMoment(data_base, A_, B_, C_, featureMoments, 2)
  {
  }
  void compute_interaction();
  const char *momentName() const { return "vpMomentGravityCenter"; }
  const char *name() const { return "vpFeatureMomentGravityCenter"; }

  static unsigned int selectXg() { return 1 << 0; }

  static unsigned int selectYg() { return 1 << 1; }
};
 
#endif
#endif